1. Field of the Invention
This invention relates to a technology for protecting a connected part of a wire and a terminal.
2. Description of the Related Art
Conventionally, a terminal-fitted wire disclosed in Japanese Unexamined Patent Publication No. 2000-285983 is known. In Japanese Unexamined Patent Publication No. 2000-285983, a crimping barrel of a ground terminal is crimped and connected to a core exposed at a wire end and a heat shrinkable tube is mounted on that crimped part.
The terminal-fitted wire on which the heat shrinkable tube is mounted as described above can be manufactured by the following process.
First, a long wire is cut to a predetermined length, a coating at a wire end portion is stripped to expose a core at the end portion. Subsequently, the wire end portion is inserted into a compression tube. Subsequently, a terminal is crimped and connected to the core exposed at the wire end portion. Thereafter, the compression tube is moved to cover a crimped part of the wire to the core. Thereafter, the compression tube is heated to shrink and deform. In this way, the terminal-fitted wire on which the heat shrinkable tube is mounted is manufactured.
In a state where the heat shrinkable tube before shrinkage is mounted on the crimped part, this heat shrinkable tube is movable relative to the crimped part. Thus, the heat shrinkable tube may move relative to the crimped part before shrinkage and may not be able to be accurately positioned with respect to the crimped part.
The above problem occurs because a time required for thermal shrinkage of the compression tube is longer than a time required for each operation performed earlier. For example, in a general wire end processing apparatus, a time required for each of a wire measuring operation, a cutting operation, a heat shrinkable tube fitting operation, a stripping operation, a crimping operation and an operation of mounting the heat shrinkable tube on a crimped part is approximately below 1 second and, at the longest, about several seconds. Contrary to this, an operation of thermally shrinking the heat shrinkable tube takes about 10 to 20 seconds. Thus, if the above series of operations are successively performed, other respective steps need to be performed in conformity with the time required for thermal shrinkage, which results in poor operation efficiency.
If a series of steps until the heat shrinkable tube is mounted on the crimped part and the step of thermally shrinking the heat shrinkable tube are separately performed to avoid this, each of the steps until the heat shrinkable tube is mounted on the crimped part can be efficiently performed.
However, in this case, the heat shrinkable tube mounted beforehand may move in a longitudinal direction of the wire between the series of steps until the heat shrinkable tube is mounted on the crimped part and the step of thermally shrinking the heat shrinkable tube, and it is difficult to position the heat shrinkable tube to accurately cover the crimped part.
Accordingly, an object of the present invention is to enable a heat shrinkable tube to be mounted on a connecting part of a core exposed portion of a wire and a terminal with high positioning accuracy.